Encoding apparatus and method, and decoding apparatus and method for error correction

ABSTRACT

An encoding and decoding apparatus and method thereof includes first and second soft encoders, a transmission channel, and first and second soft decoders. The first soft encoder performs a first soft encoding of input data to correct errors in the input data and outputting first soft-encoded data. The second soft encoder receives the first soft-encoded data, performs a second soft encoding to determine a success or failure of the encoding of the first soft-encoded data, and outputs second soft-encoded data. The first soft decoder soft-decodes data input through a transmission channel and corresponds to the second soft encoding, and outputs first soft-decoded data. The second soft decoder receives the first soft-decoded data, soft-decodes the first soft-decoded data corresponding to the first soft encoding, and outputs second soft-decoded data and additional information indicating the success or failure of the decoding of the first soft-decoded data.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the priority of Korean Patent ApplicationNo. 2002-74639, filed on Nov. 28, 2002, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein in itsentirety by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to encoding and decoding fields,and more particularly to an encoding apparatus and method, and adecoding apparatus and method, for performing signal detection and/orerror correction by interconnecting only soft-type encoding apparatuses.

[0004] 2. Description of the Related Art

[0005] Generally, signals transmitted through various transmissionchannels, for example, a spatial medium for digital televisionbroadcasting or a recording medium, such a CD, a DVD, etc., have certainsignal distortion. In order to restore the distorted signals, varioussignal detection and error correction techniques have been developed.

[0006] Conventional data detection and error correction techniquesinclude hard encoding/decoding methods such as a Reed Solomon code, aBCH code, etc., and soft encoding/decoding methods such as a Turbo code,Low Density Parity Check (LDPC) code, etc.

[0007] A decoder that implements the hard decoding methods receives adata word including a hard value of “1” or “−1” from a demodulator, andoutputs an error-corrected data word. Further, the decoder thatimplements the soft decoding methods receives a soft value representingprobability of the data word from the demodulator, and outputs theerror-corrected data word. That is, the input of the soft decoder is nota hard value of “1” or “−1” but a soft value such as “0.8”, “−0.8”,etc., where the soft value itself includes probability of a data wordvalue being “1” or “−1”.

[0008] Meanwhile, both the decoder implementing the hard encodingmethods and the decoder implementing the soft encoding methods have afunction of adding parity information to transmission data, in order toperform the operations described above.

[0009] Such conventional techniques, which perform the data detectionand the error correction using hard coding and soft coding, include amethod which uses only either the hard coding or the soft coding, amethod which performs successive encoding/decoding by using the hardcoding and the soft coding together, a method which decodes by repeatingthe hard coding, and a method which uses the hard coding and the softcoding together but merely adds a hard-type output as additionalinformation to a soft-type output, etc.

[0010] However, all of the above conventional techniques havedifficulties in obtaining a satisfying performance in detection anderror correction performance. Specially, the conventional techniques,which merely connect the hard coding and the soft coding has a problemin that information loss occurs in a process of converting the outputinformation of the soft-type decoder into the information suitable forthe hard-type decoder, and complexity increases significantly in a caseof decoding the output information into the soft-type data.

SUMMARY OF THE INVENTION

[0011] The present invention provides a encoding apparatus and method toimprove detection and error correction performance upon data decoding byinterconnecting soft-type decoders.

[0012] The present invention also provides an encoding apparatus andmethod to improve detection and error correction performance upon datadecoding by again soft encoding after interleaving soft-encoded data.

[0013] The present invention also provides a decoding apparatus andmethod to improve detection and error correction performance byinterconnecting soft-type decoders to restore signals passed throughvarious channels or signals distorted by other sources.

[0014] The present invention also provides a decoding apparatus andmethod that soft-decodes data transmitted through various channels bysoft encoding after interleaving soft-encoded data.

[0015] The present invention also provides an encoding and decodingapparatus and method to improve a detection and error correctionperformance upon data decoding by interconnecting soft-type encoders.

[0016] Additional aspects and/or advantages of the invention will be setforth in part in the description which follows and, in part, will beobvious from the description, or may be learned by practice of theinvention.

[0017] According to an aspect of the present invention, there isprovided an encoding apparatus including: a first soft encoderperforming a first soft encoding to correct errors in input data andoutputting first soft-encoded data; and a second soft encoder receivingthe first soft-encoded data, performing a second soft encoding todetermine a success or failure of the encoding of the first soft-encodeddata, and outputting second soft-encoded data.

[0018] It is preferable that the first soft encoder uses a turboencoding method, and the second soft encoder uses a Low Density ParityCheck (LDPC) coding method.

[0019] The encoding apparatus further includes an interleaverinterleaving the first soft-encoded data in a predetermined interleavingorder. The the interleaver interleaves the first encoded data with codeblock units and generates interleaved code blocks having a same numberof code blocks as the code blocks of the second soft encoder. Also, theinterleaver interleaves an area from a middle of a code block of thefirst soft encoder to the middle of a next code block thereof as aninterleaving unit when the first and the second soft encoders have asame value in corresponding code block unit sizes, and generates theinterleaved data, wherein two code blocks of the first soft encoder haveinfluence on a creation of one code block of the second soft decoder.

[0020] According to another aspect of the present invention, there isprovided a decoding apparatus including: a first soft decoder performinga first soft decoding of input data to correct errors in the input dataand outputting first soft-decoded data; and a second soft decoderreceiving the first soft-decoded data, performing a second soft decodingof the first soft-decoded data, and outputting second soft-decoded dataand additional information indicating a success or failure of thedecoding of the first soft-decoded data.

[0021] The first soft decoder may repeatedly decode second soft-decodeddata fed back in response to the additional information indicating thefailure of decoding.

[0022] The decoding apparatus further includes: a de-interleaverde-interleaving the first soft-decoded data corresponding to aninterleaving order used upon encoding; and an interleaver which,according to the additional information, performs a hard-decision forsuccessfully decoded data to restore original data, puts a soft outputof the second soft decoder in a space of non-decoded data, performsinterleaving, and feeds back the interleaved data to the first softdecoder, wherein the first soft decoder performs repeated decoding.

[0023] Also, the decoding apparatus further includes: a de-interleaverde-interleaving the first soft-decoded data corresponding to aninterleaving order used upon encoding; an interleaver which, accordingto the additional information, performs a hard-decision for successfullydecoded data of the second soft-decoded data to restore original data,keeps a space of non-decoded data of the second soft-decoded data empty,performs interleaving, and outputs the interleaved data; and a datainsertion unit inserting an output of the first soft decoder in theempty space of the interleaved data output from the interleaver andfeeding back resulting data indicative thereof to the first softdecoder, wherein the first soft decoder performs repeated decoding.

[0024] According to still another aspect of the present invention, thereis provided an encoding and decoding apparatus including: a first softencoder performing a first soft encoding of input data to correct errorsin the input data and outputting first soft-encoded data; a second softencoder receiving the first soft-encoded data, performing a second softencoding to determine a success or failure of the encoding of the firstsoft-encoded data, and outputting second soft-encoded data; atransmission channel; a first soft decoder soft-decoding data inputthrough the transmission channel and corresponding to the second softencoding, and outputting first soft-decoded data; and a second softdecoder receiving the first soft-decoded data, soft-decoding the firstsoft-decoded data corresponding to the first soft encoding, andoutputting second soft-decoded data and additional informationindicating the success or failure of the decoding of the firstsoft-decoded data.

[0025] According to still another aspect of the present invention, thereis provided an encoding method including: performing a first softencoding of input data to correct errors in the input data andoutputting first soft-encoded data; receiving the first soft-encodeddata; performing a second soft encoding to determine a success orfailure of the encoding of the first soft-encoded data; and outputtingsecond soft-decoded data.

[0026] According to still another aspect of the present invention, thereis provided a decoding method including: performing a first softdecoding of input data to correct errors in the input data andoutputting first soft-decoded data; receiving the first soft-decodeddata; performing a second soft decoding of the first soft-decoded data;and outputting second soft-decoded data and additional informationindicating a success or failure of the decoding of the firstsoft-decoded data.

[0027] According to still another aspect of the present invention, thereis provided an encoding and decoding method including: performing afirst soft encoding of input data to correct errors in the input dataand outputting first soft-encoded data; performing a second softencoding to determine a success or failure of the encoding of the firstsoft-encoded data; soft-decoding data input through a transmissionchannel, wherein the soft-decoding corresponds to the secondsoft-encoding; soft-decoding the first soft-decoded data correspondingto the first soft-encoding; and outputting second soft-decoded data andadditional information indicating the success or failure of the decodingof the first soft-decoded data.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] These and/or other aspects and advantages of the invention willbecome apparent and more readily appreciated from the followingdescription of the embodiments, taken in conjunction with theaccompanying drawings of which:

[0029]FIG. 1 is a block diagram of a system using encoding and decodingapparatuses for error correction, according to an aspect of the presentinvention;

[0030]FIG. 2 is a block diagram of another system using the encoding andthe decoding apparatuses for error correction, according to an aspect ofthe present invention;

[0031]FIG. 3 is a block diagram of still another system using theencoding and the decoding apparatuses for error correction, according toan aspect of the present invention;

[0032]FIG. 4 shows an example of an interleaving order, according to anaspect of the present invention;

[0033]FIG. 5 shows another example of the interleaving order, accordingto an aspect of the present invention; and

[0034]FIG. 6 is a graph showing decoding performance of the decodingapparatus for error correction, according to an aspect of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Reference will now be made in detail to the aspects of thepresent invention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to the like elementsthroughout. The aspects are described below to explain the presentinvention by referring to the figures.

[0036]FIG. 1 is a block diagram of a system using encoding and decodingapparatuses for error correction, according to an aspect of the presentinvention, wherein the system includes an encoding unit for errorcorrection. The encoding unit includes a first soft encoder 111, asecond soft encoder 112, a modulator 113, a channel 121, a demodulator131. The system also includes a decoding unit for error correction,which includes a first soft decoder 132 and a second soft decoder 133.

[0037] Referring to FIG. 1, the first soft encoder 111 soft-encodesinput data according to a predetermined soft encoding method, forexample, a Low Density Parity Check (LDPC) coding method capable ofdetermining a success or a failure of decoding. The predetermined softencoding method corrects errors in input data. The second soft encoder112 also soft-encodes the soft-encoded data according to thepredetermined soft encoding method, for example, a turbo encodingmethod, in order to correct the error in the soft-encoded data outputfrom the first soft encoder 111.

[0038] The modulator 113 modulates the data encoded by the encoding unitusing a modulation method, such as a Run-Length Limit (RLL) code. Theresultant modulated data is distorted via various transmission channels121, such as a recoding medium, and is input in the form of a distortedsignal to the demodulator 131. The demodulator 131 demodulates the inputdata, according to a demodulation method corresponding to the modulationmethod used by the modulator 113, and outputs the demodulated data tothe first soft decoder 132.

[0039] The first soft decoder 132 receives the demodulated data andsoft-decodes the demodulated data according to the predetermined softdecoding method for the error correction. For example, the first softdecoder 132 turbo-decodes the demodulated data corresponding to the softencoding method used in the encoding process for the error correction,i.e., the turbo encoding method. Instead of the turbo decoding, aniterative decoding method may be used, which outputs soft output values.The second soft decoder 133 receives the data decoded by the first softdecoder 132 and soft-decodes the data according to the predeterminedsoft decoding method for the error correction. The second soft decoder133 LDPC-decodes the data corresponding to the soft encoding method usedin the encoding process for the error correction, i.e., the LDPCencoding method. Here, the LDPC decoding can determine the success orfailure of data decoding.

[0040] The second soft decoder 133 feeds back additional information tothe first soft decoder 132. The additional information indicates whetherthe soft-decoded data and the decoded data are successfully decoded,thereby performing iterative decoding. This process will now bedescribed in more detail with reference to FIGS. 2 and 3.

[0041]FIG. 2 is a block diagram of another system using encoding anddecoding apparatuses for error correction, according to an aspect of thepresent invention. The system includes a first soft encoder 211, theencoding unit for the error correction, and the decoding unit for theuser correction. The encoding unit for the error correction includes aninterleaver 212 and a second soft encoder 213, a modulator 214, achannel 221, and a demodulator 231. The decoding unit for the errorcorrection includes a first soft decoder 232, a de-interleaver 233, asecond soft decoder 234 and an interleaver 235. Here, the first and thesecond soft decoders 211 and 213 are the same devices as the first andthe second soft decoders 132 and 133 of FIG. 1, respectively, andaccordingly operate in the same manner as those of FIG. 1. Theinterleaver 212 and the decoding unit are described below.

[0042] Referring to FIG. 2, the interleaver 212 interleaves soft-encodeddata output from the first soft encoder 211. The interleaver 212 bindsand interleaves several code blocks passed through the first softencoder 211, at one time, and generates and outputs interleaved codeblocks having a same number as the code blocks of the second softencoder 213, as shown in FIG. 4.

[0043] As another example of the interleaver 212, in a case where thetwo soft encoders 211 and 213 and the two soft decoders 232 and 234 havethe same value in corresponding code block unit sizes and it isdifficult to bind and interleave several code blocks because one codeblock length is very long, an area from a middle of one code block ofthe first soft encoder 211 to the middle of the next code block thereofis interleaved as a start location of a code block of the second softencoder 213. Accordingly, interleaved code blocks are generated andprovided to the second soft encoder 213. Here, two code blocks of thefirst soft encoder 211 have influence on creation of one code block tobe subjected to the second soft encoding.

[0044] Also, the first soft decoder 232 of the decoding unit for errorcorrection receives the decoded data, turbo-decodes the demodulateddata, and generates a soft output value. The de-interleaver 233 receivesthe soft output value as a decoding block unit and de-interleaves thesoft output value to restore the original sequence thereof before beinginterleaved. The second soft decoder 234 receives and LDPC-decodes thede-interleaved data, and outputs the decoded data and a signalindicating the success or the failure of the decoding. The interleaver235 performs a hard-decision for a successfully decoded signal torestore the original signal (1/−1) in response to the signal indicatingsuccessful decoding. Further, in response to the signal indicatingfailed decoding, the interleaver 235 puts the output of the second softdecoder 234 itself in the location of a non-decoded past of the signal,performs interleaving in a reverse order of de-interleaving performed bythe de-interleaver 233, outputs the interleaved result to the first softdecoder 232, and performs repeated decoding. Therefore, it is possibleto improve the signal detection and the error correction performance.

[0045]FIG. 3 is a block diagram of still another system using theencoding and decoding apparatuses for the error correction, according toan aspect of the present invention. The system includes a first softencoder 311, the encoding unit for the error correction, and thedecoding unit for the user correction. The encoding unit for the errorcorrection includes an interleaver 312 and a second soft encoder 313, amodulator 314, a channel 321, and a demodulator 331. The decoding unitfor the error correction includes a first soft decoder 332, ade-interleaver 333, a second soft decoder 334, an interleaver 335 and adata insertion unit 336. Here, the first and second soft encoders 311and 313, the interleaver 312, the demodulator 314, the channel 321, andthe demodulator 331 are the same as their counter parts in FIG. 2, andoperate in the same manner as described with reference to FIG. 2. Thedecoding unit for the error correction is described below.

[0046] Referring to FIG. 3, the first soft decoder 332 receives andturbo-decodes the decoded data and generates the soft output value. Thede-interleaver 333 receives the soft output value as the code block unitand de-interleaves the soft output value to restore the originalsequence thereof before being interleaved. The second soft decoder 334receives and LDPC-decodes the de-interleaved data and outputs thedecoded data and the signal indicating the success or failure of thedecoding. The interleaver 335 performs the hard-decision for asuccessfully decoded signal in response to the signal indicatingsuccessful decoding to restore the original signal (1/−1), performsinterleaving in a reverse order of the de-interleaving performed by thede-interleaver 333, and arranges the resulting data in the same sequenceas output data of the first soft decoder 332. When interleaving isperformed, a space for the non-decoded data is kept empty.

[0047] The data insertion unit 336 receives the interleaved data fromthe interleaver 335 according to the sequence of the output data of theinterleaver 335 and the sequence of the output data of the first softdecoder 332. The data insulation unit 336 inserts the output data fromthe first soft decoder 332 in an empty space of the output data of theinterleaver 335, and, then, outputs resultant data to the first softdecoder 332. The first soft decoder 332 soft-decodes the received dataagain.

[0048] Accordingly, the error correction performance is improved byrepeatedly decoding for correcting errors in the error-corrected data.Also, by interleaving two code blocks for the first soft encoding andcreating one code block for the second soft encoding, according to theinterleaving order shown in FIG. 5, in the interleaving process of thedata encoding apparatus, the data in the two code blocks subjected tothe first soft decoding is distributed and arranged appropriately to onecode block, which is subjected to the second soft decoding to improveerror correction performance. Also, an interleaving unit is implementedas one code block, which facilitates interleaving. Here, the operationcount of such repeated decoding can be determined by the designer of thedecoding apparatus.

[0049]FIG. 6 is a graph showing decoding performance of the decodingapparatus for the error correction, according to an aspect of thepresent invention. A plot denoted by “¤” represents the error rate ofthe data before being soft-decoded, the plot denoted by “∘” representsthe error rate of the output data after the turbo type soft decoding isperformed, the plot denoted by “X” represents the error rate of theoutput data after the data soft-decoded by the turbo decoding method issoft-decoded using the LDPC decoding method, and the plot denoted by “Δ”represents the error rate of the output data after the data soft-decodedby the LDPC decoding method is again decoded using the turbo decodingmethod. As illustrated in FIG. 6, it is seen that as the decodingoperations are repeated, the error rate is reduced.

[0050] The present invention may be embodied as a program stored on acomputer readable medium that can be run on a general computer. Here,the computer readable medium includes but is not limited to storagemedia such as magnetic storage media (e.g., ROM's, floppy disks, harddisks, etc.), optically readable media (e.g., CD-ROMs, DVDs, etc.), andcarrier waves (e.g., transmission over the Internet). The presentinvention may also be embodied as a computer readable program code unitstored on a computer readable medium, for causing a number of computersystems connected via a network to affect distributed processing.

[0051] As described above, according to an aspect of the presentinvention, it is possible to improve signal detection and errorcorrection performance without information loss, by encoding data usinginterconnection of soft coding methods and repeatedly decoding theencoded data.

[0052] Although a few aspects of the present invention have been shownand described, it would be appreciated by those skilled in the art thatchanges may be made in this aspect without departing from the principlesand spirit of the invention, the scope of which is defined in the claimsand their equivalents.

What is claimed is:
 1. An encoding apparatus, comprising: a first softencoder performing a first soft encoding to correct errors in input dataand outputting first soft-encoded data; and a second soft encoderreceiving the first soft-encoded data, performing a second soft encodingto determine a success or failure of the encoding of the firstsoft-encoded data, and outputting second soft-encoded data.
 2. Theencoding apparatus of claim 1, wherein the first soft encoder uses aturbo encoding method.
 3. The encoding apparatus of claim 1, wherein thesecond soft encoder uses a Low Density Parity Check (LDPC) codingmethod.
 4. The encoding apparatus of claim 1, further comprising: aninterleaver interleaving the first soft-encoded data in a predeterminedinterleaving order.
 5. The encoding apparatus of claim 4, wherein theinterleaver interleaves the first encoded data with code block units andgenerates interleaved code blocks having a same number of code blocks asthe code blocks of the second soft encoder.
 6. The encoding apparatus ofclaim 4, wherein the interleaver interleaves an area from a middle of acode block of the first soft encoder to the middle of a next code blockthereof as an interleaving unit when the first and the second softencoders have a same value in corresponding code block unit sizes, andgenerates the interleaved data, wherein two code blocks of the firstsoft encoder have influence on a creation of one code block of thesecond soft decoder.
 7. A decoding apparatus, comprising: a first softdecoder performing a first soft decoding of input data to correct errorsin the input data and outputting first soft-decoded data; and a secondsoft decoder receiving the first soft-decoded data, performing a secondsoft decoding of the first soft-decoded data, and outputting secondsoft-decoded data and additional information indicating a success orfailure of the decoding of the first soft-decoded data.
 8. The decodingapparatus of claim 7, wherein the first soft decoder uses a turbodecoding method.
 9. The decoding apparatus of claim 7, wherein thesecond soft decoder uses a Low Density Parity Check (LDPC) decodingmethod.
 10. The decoding apparatus of claim 7, wherein the first softdecoder repeatedly decodes the second soft-decoded data fed back inresponse to the additional information indicating the failure of thedecoding.
 11. The decoding apparatus of claim 7, further comprising: ade-interleaver de-interleaving the first soft-decoded data correspondingto an interleaving order used upon encoding; and an interleaver which,according to the additional information, performs a hard-decision forsuccessfully decoded data to restore original data, puts a soft outputof the second soft decoder in a space of non-decoded data, performsinterleaving, and feeds back the interleaved data to the first softdecoder, wherein the first soft decoder performs repeated decoding. 12.The decoding apparatus of claim 7, further comprising: a de-interleaverde-interleaving the first soft-decoded data corresponding to aninterleaving order used upon encoding; an interleaver which, accordingto the additional information, performs a hard-decision for successfullydecoded data of the second soft-decoded data to restore original data,keeps a space of non-decoded data of the second soft-decoded data empty,performs interleaving, and outputs the interleaved data; and a datainsertion unit inserting an output of the first soft decoder in theempty space of the interleaved data output from the interleaver andfeeding back resulting data indicative thereof to the first softdecoder, wherein the first soft decoder performs repeated decoding. 13.An encoding and decoding apparatus, comprising: a first soft encoderperforming a first soft encoding of input data to correct errors in theinput data and outputting first soft-encoded data; a second soft encoderreceiving the first soft-encoded data, performing a second soft encodingto determine a success or failure of the encoding of the firstsoft-encoded data, and outputting second soft-encoded data; atransmission channel; a first soft decoder soft-decoding data inputthrough the transmission channel and corresponding to the second softencoding, and outputting first soft-decoded data; and a second softdecoder receiving the first soft-decoded data, soft-decoding the firstsoft-decoded data corresponding to the first soft encoding, andoutputting second soft-decoded data and additional informationindicating the success or failure of the decoding of the firstsoft-decoded data.
 14. The encoding and decoding apparatus of claim 13,wherein the first soft encoding is implemented by a turbo encodingmethod.
 15. The encoding and decoding apparatus of claim 13, wherein thesecond soft encoding is implemented by a Low Density Parity Check (LDPC)coding method.
 16. The encoding and decoding apparatus of claim 13,further comprising: an interleaver which interleaving the firstsoft-encoded data in a predetermined interleaving order.
 17. Theencoding and decoding apparatus of claim 16, wherein the interleaverinterleaves the first encoded data with code block units and generatesinterleaved code blocks having a same number of code blocks as the codeblocks of the second soft encoder.
 18. The encoding and decodingapparatus of claim 16, wherein the interleaver interleaves an area froma middle of a code block of the first soft encoder to the middle of anext code block thereof as an interleaving unit when the first and thesecond soft encoders have a same value in corresponding code block unitsizes, and generates the interleaved data, wherein two code blocks ofthe first soft encoder have influence on a creation of one code block ofthe second soft decoder.
 19. The encoding and decoding apparatus ofclaim 13, wherein the first soft decoder repeatedly decodes the secondsoft-decoded data fed back in response to the addition informationindicating the failure of decoding.
 20. The encoding and decodingapparatus of claim 13, further comprising: a de-interleaverde-interleaving the first soft-decoded data corresponding to aninterleaving order used upon encoding; and an interleaver which,according to the additional information, performs a hard-decision forsuccessfully decoded data to restore original data, puts a soft outputof the second soft decoder in a space of non-decoded data, performsinterleaving, and feeds back the interleaved data to the first softdecoder, wherein the first soft decoder performs repeated decoding. 21.The encoding and decoding apparatus of claim 13, further comprising: ade-interleaver de-interleaving the first soft-decoded data correspondingto an interleaving order used upon encoding; an interleaver which,according to the additional information, performs a hard-decision forsuccessfully decoded data of the second soft-decoded data to restoreoriginal data, keeps a space of non-decoded data of the secondsoft-decoded data empty, performs interleaving, and outputs theinterleaved data; and a data insertion unit inserting an output of thefirst soft decoder in the empty space of the interleaved data outputfrom the interleaver and feeding back resulting data indicative thereofto the first soft decoder, wherein the first soft decoder performsrepeated decoding.
 22. An encoding method, comprising: performing afirst soft encoding of input data to correct errors in the input dataand outputting first soft-encoded data; and performing a second softencoding to determine a success or failure of the encoding of the firstsoft-encoded data.
 23. The encoding method of claim 22, furthercomprising: implementing the first soft encoding using a turbo encodingmethod.
 24. The encoding method of claim 22, further comprising:implementing the second soft encoding is using a Low Density ParityCheck (LDPC) coding method.
 25. The encoding method of claim 22, furthercomprising interleaving the first soft-encoded data in a predeterminedinterleaving order.
 26. The encoding method of clam 25, wherein in theinterleaving, the first soft-encoded data is interleaved with code blockunits, and generates interleaved code blocks having a same number ofcode blocks as the code blocks of the second soft encoder.
 27. Theencoding method of claim 25, wherein in the interleaving, an area from amiddle of a soft code block to the middle of a next soft code blockthereof is interleaved as an interleaving unit when the first and thesecond soft encoders have a same value in corresponding code block unitsizes, and generates interleaved data, wherein two code blocks of thefirst soft encoder have influence on a creation of one code block of thesecond soft decoder.
 28. A decoding method, comprising: performing afirst soft decoding of input data to correct errors in the input dataand outputting first soft-decoded data; and performing a second softdecoding of the first soft-decoded data.
 29. The decoding method ofclaim 28, further comprising: implementing the first soft decoding usinga turbo decoding method.
 30. The decoding method of claim 28, furthercomprising: implementing the second soft decoding is using a Low DensityParity Check (LDPC) decoding method.
 31. The decoding method of claim28, wherein the first soft-decoding further comprises: performingrepeated decoding of the second soft-decoded data fed back in responseto the additional information indicating the failure of the decoding.32. The decoding method of claim 28, further comprising: de-interleavingthe first soft-decoded data corresponding to an interleaving order usedupon encoding; and according to the additional information performing ahard-decision to successfully decode the data to restore original data,putting a soft output of the second soft decoder in a space ofnon-decoded data, interleaving the data, and feeding back theinterleaved data to the first soft decoder, wherein the first softdecoding is performed repeatedly.
 33. The decoding method of claim 28,further comprising: de-interleaving the first soft-decoded datacorresponding to the interleaving order used upon decoding; according tothe additional information, performing a hard-decision to successfullydecode the data of the second soft-decoded data to restore originaldata, keeping a space of non-decoded data of the second soft-decodeddata empty, interleaving, and outputting the interleaved data; insertingthe first soft-decoded data in the empty space of the interleaved data;and performing the first soft decoding of the resulting data, whereinthe first soft decoding is performed repeatedly.
 34. An encoding anddecoding method, comprising: performing a first soft encoding of inputdata to correct errors in the input data and outputting firstsoft-encoded data; performing a second soft encoding to determine asuccess or failure of the encoding of the first soft-encoded data;soft-decoding data input through a transmission channel, wherein thesoft-decoding corresponds to the second soft-encoding; soft-decoding thefirst soft-decoded data corresponding to the first soft-encoding; andoutputting second soft-decoded data and additional informationindicating the success or failure of the decoding of the firstsoft-decoded data.
 35. The encoding and decoding method of claim 34,further comprising: implementing the first soft encoding using a turboencoding methods.
 36. The encoding and decoding method of claim 34,further comprising: implementing the second soft decoding is using a LowDensity Parity Check (LDPC) coding method.
 37. The encoding and decodingmethod of claim 34, further comprising: interleaving the firstsoft-encoded data in a predetermined interleaving order.
 38. Theencoding and decoding method of claim 37, wherein in the interleaving,the first soft-encoded data is interleaved with code block units, andgenerates interleaved code blocks having a same number of code blocks asthe code blocks of the second soft encoder.
 39. The encoding anddecoding method of claim 37, wherein in the interleaving, an area from amiddle of a soft code block to the middle of a next soft code block isinterleaved as an interleaving unit when the first and the secondsoft-encoded data have a same value in corresponding code block unitsizes, to generate interleaved data, wherein two first soft code blockshave influence on a creation of one second soft code block.
 40. Theencoding and decoding method of claim 34, wherein the first softdecoding further comprises: performing repeated decoding of the secondsoft-decoded data fed back in response to the addition informationindicating the failure of the decoding.
 41. The encoding and decodingmethod of claim 34, further comprising: de-interleaving the firstsoft-decoded data corresponding to the interleaving order used uponencoding; and according to the additional information performing ahard-decision to successfully decode the data to restore original data,putting a soft output of the second soft decoder in a space ofnon-decoded data, interleaving the data, and feeding back theinterleaved data to the first soft decoder, wherein the first softdecoding is performed repeatedly.
 42. The encoding and decoding methodof claim 34, further comprising: de-interleaving the first soft-decodeddata corresponding to an interleaving order used upon encoding;according to the additional addition, performing a hard-decision tosuccessfully decode the data of the second soft-decoded data to restoreoriginal data, keeping a space of non-decoded data of the secondsoft-decoded data empty, interleaving, and outputting interleaved data;and inserting the first soft-decoded data in the empty space of theinterleaved data and performing the first soft decoding of result dataindicative thereof, wherein the first soft decoding is performedrepeatedly.
 43. A computer readable medium storing a computer program toexecute an encoding method, comprising: performing a first soft encodingof input data to correct errors in the input data and outputting firstsoft-encoded data; and performing a second soft encoding to determine asuccess or failure of the encoding of the first soft-encoded data.
 44. Acomputer readable medium storing a computer program to execute adecoding method, comprising: performing a first soft decoding of inputdata to correct errors in the input data and outputting firstsoft-decoded data; and performing a second soft decoding of the firstsoft-decoded data.
 45. A computer readable medium storing a computerprogram to execute an encoding and decoding method, comprising:performing a first soft encoding of input data to correct errors in theinput data and outputting first soft-encoded data; performing a secondsoft encoding to determine a success or failure of the encoding of thefirst soft-encoded data; soft-decoding data input through a transmissionchannel, wherein the soft-decoding corresponds to the secondsoft-encoding; soft-decoding the first soft-decoded data correspondingto the first soft-encoding; and outputting second soft-decoded data andadditional information indicating the success or failure of the decodingof the first soft-decoded data.